The present invention relates to the field of dispensers for transfer adhesives. As used herein, the term "transfer adhesive" refers to an adhesive which is originally disposed on a backing, or liner, and which is separated from the backing and applied to a surface.
Transfer adhesives have many uses. For example, they can be used to attach papers to a bulletin board, or similar surface. When a web of transfer adhesive has been applied to the surface, a paper pressed onto the adhesive will adhere to that surface. If the proper transfer adhesive composition is chosen, the paper can be easily removed from the surface without tearing.
One example of a dispenser for a transfer adhesive is shown in U.S. Pat. No. 3,969,181. In the device shown in the latter patent, a tape, which includes the transfer adhesive and a backing, is fed from a supply reel and around a tape roller. The backing, after being separated from the adhesive, is wound around a take-up reel. The reels are normally prevented from moving by a detent engaging a serration on a gear. The reels are allowed to move only when a trigger, releasing the detent, is depressed.
The prior art contains numerous other examples of devices for dispensing tapes having adhesives and liners. One such device is shown in U.S. Pat. No. 3,839,127, which shows a deflecting member for diverting the waste liner from the adhesive, after the adhesive and the liner are separated. Other devices involving tapes and liners are shown in U.S. Pat. Nos. 3,509,000 and 4,336,097.
It is important that a tape dispenser not dispense any tape when the device is not in use. In U.S. Pat. No. 3,969,181, described above, the trigger mechanism prevents the dispenser reels from rotating except when the trigger is depressed. In other devices the trigger may assume a different form, or it may appear on a different part of the dispenser.
Trigger-operated dispensers, of the type described above, are inconvenient or confusing, for many users. To operate such a dispenser, the user must perform several operations in a particular order. First the user must apply the device to the working surface. Then, the user must depress the trigger. Then, the device must be moved along the surface, to apply the adhesive, while the trigger is held in the operating position. Finally, the trigger is released and the device laid aside. If the steps described above are not performed in the correct order, the dispenser will not operate.
The present invention makes it easier to use a dispenser for a transfer adhesive, by providing an improved device which is actuated automatically when it is used. That is, the very act of pressing the dispenser against the working surface enables the supply and take-up reels to rotate. The dispenser returns automatically to the disabled position when the device is laid aside.
The device also has other advantages. It includes means for assuring that the tape will be maintained in a taut position. And it is designed to facilitate the removal of spent backing from the device, without dismantling the take-up reel.